thompson



:Z'Sheets-SMet 1.

(No Model.)

J. THOMPSON.

TRAVELING CRANE AND DERRIGK.

. Patented Peb.27,1883.

(No Model.) 2 Sheets-Sheet 2.

J. THOMPSON.

TRAVELING CRANE AND DERRICK.

' No. 272.987. Patented Peb.'27,1883.

5. Plwto-Lithognyher. Washinglon, D, C.

UNITED STATES JOHN THOMPSON, OF BUOYRUS, OHIO, ASSIGNOR TO THE BUOYRUS FOUNDRY AND MANUFACTURING COMPANY, OF SAME PLACE.

TR AVELING'CRANE AND DERRICK.

SPECIFICATION forming part of Letters Patent No. 272,987, dated February 27, 1883.

Application filed January 17, 1883. (No model.)

1'0 all whom it may concern 7 Be it known that I, JOHN THOMPSON, of

. Bucyrus,in the county of Crawford and State of Ohio, haveinvented certain Improvements in Traveling Cranes; and I hereby declare the following to be a full, clear, and exact descrip' tion of the same, reference being had to the accompanying drawings, making part of this specification, in which- Figure 1 illustrates a section of a movable platform, car, or carriage, which carries the crane and the mast of the crane, with myimprovements. Fig. 2 is a plan view of the same. Fig. 3 is a detail elevation of the jack-arm, partiallyin section.

My invention relates to traveling cranes or derricks, which are used for a variety of well- 7 known purposes, and has for its object to inmake and use my invention, I will proceed to describe the manner in which I have carried it out. r

In the said drawings, A is the movable platform or car supporting the mast B of the traveling crane or derrick. In the drawings the boom and working parts thereof are not shown, as they are not material to my present invention.

On the top of the platform, in the rear of the mast, is bolted transversely a channel-bar, 0,.

and at its end, and between ribs a a, is bolted a casting, I), for a purpose hereinafter set forth.

The casting D consists of a base-plate, b, an upright plate or prOjeGtiOn,d, having two ears, 6 e, projecting outwardly at right angles to its face, and two cars, i t, projecting inwardly at an angle'toward the mast,and having their lower edges integral with bed-plate b. Pivoted to the mast,nearitsupperend, atk, isone end of a brace, E, which extendsto casting D, and is bolted in the ears i t, as shown.

ing-pieces, preferably of channeliron, F G, (shown in dotted lines.) Bolted at its ends to F and Gisa short channel-iron piece, H, against each side of which rests a leg or bar, I 1, forming the projecting jack-arm. These bars I I have their inner ends resting between the flanges of channel-piece G. and are held to piece H by bolt 19, and have securely bolted through their outer ends a head, J, which is tapped to receive a jack-screw, L, and is provided with cars it a on the side next to the car. A diagonal brace, M, has one end holted in the cars a n and the other end bolted in the ears i} i. When a load is to be lifted, or other heavy work performed, the screw L is run down until its lower end has a firm hearing on the ground and the tipping of the platform is prevented.

By the use of this jack-arm I am enabled to cut off or round oii' the'plattorm at its ends, and thereby work may be done close to and at right angles with the car, as shown at tt, Fig. 2. When the platform or car is to be transported, boltsp and q are removed, and the entire jack-arm is removed and stowed upon the car. Any number of these jack-arms may be applied to one car without departing from the spirit of my invention, and if found desirable the brace M may be dispensed with, as it is only an additional safeguard to bars I 1.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is-

1. In a traveling crane or derrick, the supporting-platform A, in combination with a jack-arm adapted to increase the length or breadth of the bearing of said platform, substantially as set forth.

2. The jack-arn1 consisting of the bars I I, head J, screw L, casting D, constructed as described, and channel-pieces G and H, all constructed, arranged, and operated as described.

3. The jack-arm constructed substantially as describethin combination with the brace E, pivoted to the mast at k and to ears 6 t, substantially as specified.

4. In combination with a crane or derrick and ajack-arm adapted to enlarge the bearings of a traveling crane, the plattorm A, having its corners cut away, for the purpose set forth.

- JOHN THOMPSON.

Witnesses:

Wu Awrm: Ann-Ms.

too 

